Regeneration and recycling of contaminated solutions from aluminum and tin washer processes

Abstract

A process is described for regenerating and recycling a contaminated solution recovered from an aluminum or tin washer process wherein the contaminated solution contains contaminants comprising inorganic soils, organic soils, or both as a result of the use of the solution in the washer process, which comprises (A) regenerating said solution by (A-1) extracting said contaminants from the solution in a manner which does not substantially reduce the amount of any chemicals present in the solutions prior to use; and (A-2) selectively replenishing chemicals as required; and (B) recycling the regenerated solution to the washer process. The process of the present invention significantly reduces the amount of waste water containing chemicals which must be discarded or treated in waste treatment facilities. The process also reduces the amount of process chemicals and water necessary for maintaining the washer processes used for aluminum and tin coil and container washer processes.

We claim: 
     
       1. A process comprising: regenerating and recycling, a contaminated solution recovered from an aluminum or tin washer process wherein the contaminated solution contains contaminants comprising inorganic soils, organic soils, or both as a result of the use of the solution in the washer process, by, (A) regenerating said solution by (A-1) extracting said contaminants from the solution in a manner which does not substantially reduce the amount of any chemicals present in the solutions prior to use; and   (A-2) selectively replenishing chemicals as required; and     (B) recycling the regenerated solution to the washer process.   
     
     
       2. The process of claim 1 wherein the solution is regenerated by extracting the contaminants in (A-1) by, (a) ion exchange resin adsorption;   (b) filtration;   (c) precipitation;   (d) deposition of metal on a reactive substrate;   (e) electrowinning; or   (f) a combination of one or m of (a) through (e).   
     
     
       3. A process comprising: regenerating and recycling a contaminated solution recovered from a multistage aluminum or tin plate washer process comprising cleaner, conditioning, pretreatment and/or rinse stages wherein the contaminated solution contains contaminants comprising inorganic soils, organic soils, or both as a result of the use of the solution in the washer process by, (A) regenerating said solution by (A-1) extracting said contaminants from the solution in a manner which does not substantially reduce the amount of chemicals present in the solutions prior to use; and   (A-2) selectively replenishing chemicals as required; and     (B) recycling the regenerated solution to the pretreatment, cleaner, conditioning, or rinse stage of the container washer process.   
     
     
       4. The process of claim 3 wherein the solution is recovered from a container or coil line washer process. 
     
     
       5. The process of claim 3 wherein the solution is regenerated by extracting the contaminants in (A-1) by (a) ion exchange resin adsorption;   (b) filtration;   (c) precipitation;   (d) deposition of metal on a reactive substrate;   (e) electrowinning; or   (f) a combination of one or more of (a) through (e).   
     
     
       6. The process of claim 3 wherein the solution which is regenerated is an alkaline cleaner solution. 
     
     
       7. The process of claim 3 wherein the solution which is regenerated is an acid cleaner solution. 
     
     
       8. The process of claim 3 wherein the solution which is regenerated is a rinse, conditioner or pretreatment solution. 
     
     
       9. The process of claim 3 wherein said contaminants comprise organic oil, and the oil is extracted in step (A) by filtration. 
     
     
       10. The process of claim 3 wherein said contaminants comprise organic oil, and the oil is extracted in step (A) by thermal separation of the oil from the solution followed by filtration, skimming, or both. 
     
     
       11. The process of claim 3 wherein said contaminants comprise inorganic soil, and the inorganic soil is extracted by ion exchange resin adsorption. 
     
     
       12. The process of claim 3 wherein said contaminants comprise inorganic soil, and the inorganic soil is extracted by precipitation, settling or filtration. 
     
     
       13. A process comprising: regenerating and recycling contaminated cleaner or rinse solutions recovered from a multi-stage aluminum container or roil washer process wherein the contaminated solution contains contaminants comprising inorganic soils, organic soils, or both as a result of the use of the solution in the washer process by, (A) regenerating said solution by (A-1) extracting said contaminants from the solution in a manner which does not substantially reduce the amount of any chemicals present in the solution prior to use; and   (A-2) selectively replenishing chemicals as required; and     (B) recycling the regenerated solution to the cleaner or rinse stage of the container washer process.   
     
     
       14. The process of claim 13 wherein the cleaning solution is regenerated in step (A-1) by extracting the contaminants by (a) ion exchange resin adsorption;   (b) filtration;   (c) precipitation;   (d) deposition of metal on a reactive substrate;   (e) electrowinning; or   (f) a combination of one or more of (a) through (e).   
     
     
       15. The process of claim 13 wherein the solution is an alkaline cleaner solution. 
     
     
       16. The process of claim 13 wherein the solution is an acid cleaner solution. 
     
     
       17. The process of claim 13 wherein the solution is an aqueous rinse solution. 
     
     
       18. The process of claim 13 wherein the organic soils comprise forming or rolling oils. 
     
     
       19. The process of claim 13 wherein the inorganic soils comprise aluminum fines, aluminum oxides, and water-soluble aluminum derivatives. 
     
     
       20. The process of claim 13 wherein the inorganic soils are extracted in step (A-1) by ion exchange resin adsorption. 
     
     
       21. The process of claim 13 wherein the contaminants comprise inorganic soil which is extracted in step (A-1) by precipitation and filtration. 
     
     
       22. The process of claim 13 wherein the inorganic soils are extracted by deposition on a reactive substrate, 
     
     
       23. A process comprising: regenerating and recycling a contaminated cleaner solution recovered from the cleaner stage of a multi-stage aluminum container washer process where the contaminated solution contains contaminants comprising inorganic soils and organic soils as a result of the use of the solution in the cleaner stage by, (A-1) regenerating said solution by (A-1-a) extracting the organic soils by filtration;   (A-1-b) extracting the inorganic soils by ion exchange resin absorption, deposition on a reactive substrate, or precipitation and filtration; or   (A-1-c) combinations of (A-1) and (A-2); and     (A-2) selectively replenishing any chemicals as required; and (B) recycling the regenerated solution to the cleaner stage of the container washer process.     
     
     
       24. The process of claim 23 wherein the cleaner solution is an alkaline cleaner solution. 
     
     
       25. The process of claim 23 wherein the cleaner solution is an acid cleaner solution. 
     
     
       26. The process of claim 23 wherein the cleaner solution is an alkaline cleaner solution, and the inorganic soils are extracted in step (A-1-b) by precipitation and filtrating and wherein precipitation is aided by reducing the pH of the contaminated solution to about 10 by the addition of an acid. 
     
     
       27. The process of claim 23 wherein the inorganic soils are extracted in step (A-1-b) by ion exchange resin adsorption. 
     
     
       28. The process of claim 23 wherein the inorganic soils are extracted in step (A-1-b) by deposition on a reactive substrate. 
     
     
       29. The process of claim 23 wherein the inorganic soils are extracted by contact with a cationic polymer, an anionic polymer, or mixtures thereof.